title: Liposomal targeting of glucocorticoids to the inflamed synovium inhibits cartilage matrix destruction during murine antigen-induced arthritis.
abstract: Encapsulation of glucocorticoids into long-circulating liposomes provides targeting of these drugs to the inflamed synovium in experimental arthritis and thereby strongly improves their therapeutic index. The goal of this study was to evaluate the effect and mechanisms of intravenous liposomal delivery of prednisolone phosphate (Lip-PLP) on protease mediated cartilage destruction during murine antigen-induced arthritis (AIA). Mice treated with a single injection of Lip-PLP showed a pronounced suppression of synovial immune cell infiltration compared to control, PBS-treated mice. Liposomal PLP also significantly suppressed interleukin 1β (3.6 fold) in the synovium, but not in the blood serum. Furthermore, expression of the proteases MMP-3, -9, -13 and -14 and ADAMTS-4 and -5 was suppressed by Lip-PLP in the synovium, but not within the articular cartilage of the femur and tibia, demonstrating the specific action of Lip-PLP on the synovium. Lip-PLP is phagocytosed by macrophages in vitro and suppresses their expression of IL-1β and MMPs after LPS activation. Moreover, Lip-PLP suppresses destruction of the cartilage matrix during AIA mediated by active MMPs and ADAMTS, as assessed by immunostaining of their respective neoepitopes VDIPEN and NITEGE in various cartilage layers of the knee joint.
  
  
  CONCLUSIONS
  liposomal delivery of glucocorticoids protects against cartilage matrix destruction during experimental arthritis by inhibiting protease expression and activity in the inflamed synovium.
authors.affiliation: Rheumatology Research and Advanced Therapeutics, Department of Rheumatology, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands.
authors.forename: W
authors.initials: W
authors.lastname: Hofkens
authors.forename: G
authors.initials: G
authors.lastname: Storm
authors.forename: W B
authors.initials: WB
authors.lastname: van den Berg
authors.forename: P L
authors.initials: PL
authors.lastname: van Lent
mesh_terms: D051722:ADAM Proteins / Q000187:drug effects / Q000378:metabolism; D000818:Animals; D000941:Antigens / Q000633:toxicity; D001169:Arthritis, Experimental / Q000188:drug therapy* / Q000473:pathology; D002358:Cartilage, Articular / Q000187:drug effects / Q000473:pathology; D003692:Delayed-Action Preparations; D016503:Drug Delivery Systems; D005938:Glucocorticoids / Q000008:administration & dosage / Q000494:pharmacology*; D053583:Interleukin-1beta / Q000378:metabolism; D008081:Liposomes; D008297:Male; D020782:Matrix Metalloproteinases / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D011239:Prednisolone / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000494:pharmacology; D013583:Synovial Membrane / Q000187:drug effects / Q000473:pathology
chemical_list: D000941:Antigens; D003692:Delayed-Action Preparations; D005938:Glucocorticoids; D053583:Interleukin-1beta; D008081:Liposomes; C009022:prednisolone phosphate; D011239:Prednisolone; D051722:ADAM Proteins; D020782:Matrix Metalloproteinases